The external surfaces of various organisms such as humans, lower animals, and plants (e.g., "skin"), from time to time, need to be cleaned and, desirably, disinfected. For example, abrasions, skin infections, pre-surgical scrubs, various swellings, chronic inflammatory conditions, sprains, bruises, obstinate ulcers, and the umbilical stump of foals and calves need a disinfecting cleaning. Illustratively, to protect a dairy cow, its teats are cleaned before and after milking to reduce and/or prevent intramammary infections.
In this regard, in the late 1960's, the dairy industry adopted germicidal teat dipping to reduce the rate of new intrammary infections. Iodine based germicidal teat dips are recognized as effective and today, commercial teat dips frequently contain 0.5% or 1.0% active iodine aqueous solutions, and are sometimes formulated with an emollient such as 10% glycerine. An alternative aqueous teat dip currently in use contains povidone-iodine ("PVP-Iodine"). Such teat dips are either sprayed onto the teats or the teat is dipped into a cup of the disinfectant. In pre-milking, after the teat dip has been applied, a paper towel wipe is used to remove the excess dip 30-60 seconds after exposure. In post milking the germicidal solution is not wiped off.
However, various mastitis pathogens can be transmitted from infected to non-infected cows through the teat dipping cups and sprays often fail to contact the teat duct adequately and contribute to costly over spraying. Furthermore, the incorrect use of concentrated products such as udder washes or cleaners for teat dips can result in severe lesions within one or two applications. Improper mixing, freezing or simply production accidents also produce a variety of lesions. A further problem is that teat dips frequently dry out the teat skin, or, during extremely cold weather teat dips may promote teat chapping: teats exposed to extreme cold while wet with dip may freeze. Additional severe problems may occur when highly acidic utensil sanitizers or udder washes are used as teat dips. The use of such products, for even a few milkings, can cause severe teat lesions that may predispose to a serious outbreak of mastitis within a herd.
In 1996, Applied Microbiology launched Wipeout, a pre-moistened dairy wipe containing the antimicrobial peptide nisan. This wipe simultaneously applied a germicidal agent and cleaned the teats before the teat was attached to the milking machine. As these wipes incorporate an alcohol-in-water solution, their storage requires special barrier packaging and they have a limited shelf life. In addition, the add on weight of these pre-moistened towels increases the cost of shipping them.
Currently there are only two over-the-counter antimicrobial ingredients approved by both the U.S. Food and Drug Administration and the Environmental Protection Agency for use in skin antisepsis, first aid, wound care, and hard surface sanitizing or disinfecting applications.
The first, ethyl alcohol, has a long history of safe and effective use. However, there is a long list of negative attributes associated with the use of ethyl alcohol. It dries and irritates healthy skin and stings injured or abraded skin. Moreover, as ethyl alcohol is highly volatile, it dissipates rapidly and thus has a short duration of antimicrobial effectiveness. Other disadvantages of ethyl alcohol include its stringent regulation by governmental agencies, its ability to erode some metals, its ability to remove paint and varnish and its ability to delaminate some plastics.
The other approved antimicrobial ingredient, PVP-iodine, has a variety of uses in health care on both skin and hard surfaces. PVP-iodine also has negative attributes that limit its use. For example, aqueous iodophor solutions such as PVP-iodine temporarily discolor and irritate skin, and can also corrode some metals.
The problems associated with these antimicrobial ingredients and their relatively high cost have limited their usage. Less versatile, less expensive and less effective ingredients such as bleach are commonly used on hard surfaces, and either benzalkonium-chloride or Triclosan is typically used on skin, both as aqueous solutions.
The use of premoistened wipes to deliver aqueous solutions containing alcohol or Povidone iodine to sanitize skin or to disinfect hard surfaces is longstanding. But such wet wipes are expensive because they require barrier packaging to prevent evaporation or "dryout". Also contributing to the expense of such wipes is the need for special binder-free substrates for hydro-alcoholic formulations and starch-free substrates for aqueous iodophor formulations. Thus, the use of these ingredients has been limited and reserved for higher risk healthcare and medical environments where other considerations justify the higher costs.
Such prior art references as U.S. Pat. Nos. 3,227,614; 3,283,357; 4,257,924; and 4,692,374 and Australian Patent No. 72440/87 disclose systems of diluting active disinfectants and cleaning agents in a carrier, applying the surplus of the carrier containing the active ingredients onto a specific applicator material and subsequently drying the material with the carrier and active ingredient. These methods were used in the prior art because it was a convenient way to evenly disperse a specific amount of active ingredient on an applicator material. For example, U.S. Pat. No. 3,227,614 uses a mineral oil as a carrier and adds an excess of detergent to counteract and emulsify the oily properties of the mineral oil carrier. The other references noted above use water, alcohol or combinations thereof, all followed by a drying step.
U.S. Pat. No. 5,091,102, "Method of Making a Dry Antimicrobial Fabric" contacts a substantially dry antimicrobial treated skin wipe with water to activate the germicidal agent.